arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1003.0283astro-ph.HE
收藏

M82超铝X射线源X射线热主导态的识别

Identification of the X-Ray Thermal Dominant State in an Ultraluminous X-Ray Source in M82

Hua Feng, Philip Kaaret

摘要:

黑洞双星(BHB)中的热主导态是很好理解的,但在超亮X射线源(ULX)中很少见到。利用钱德拉和XMM-牛顿同时观测M82,我们报告了第一个可能的识别的热主导状态的ULX的基础上消失的X射线振荡,低定时噪声,和光谱占主导地位的光盘发射与光度变化的4次幂的磁盘温度。这表明ULX类似于银河系BHB。最亮的X射线谱可以用相对论盘模型拟合,该模型既可以是高度超爱丁顿(L_disk/L_Edd = 160)的非旋转黑洞,也可以是接近爱丁顿(L_disk/L_Edd ~ 2)的快速旋转黑洞。后一种解释是更可取的,因为在银河系黑洞和活动星系核中不存在这种高度超爱丁顿态,并表明M82中的ULX包含一个200-800太阳质量的黑洞,其自旋接近最大值。在较长的时间尺度上,源通常停留在一个相对较低的通量水平,有规则的62天轨道调制,偶尔会出现不规则的耀斑活动。热优势态都出现在爆发期。

英文摘要:

The thermal dominant state in black hole binaries (BHBs) is well understood but rarely seen in ultraluminous X-ray sources (ULXs). Using simultaneous observations of M82 with Chandra and XMM-Newton, we report the first likely identification of the thermal dominant state in a ULX based on the disappearance of X-ray oscillations, low timing noise, and a spectrum dominated by multicolor disk emission with luminosity varying to the 4th power of the disk temperature. This indicates that ULXs are similar to Galactic BHBs. The brightest X-ray spectrum can be fitted with a relativistic disk model with either a highly super-Eddington (L_disk/L_Edd = 160) non-rotating black hole or a close to Eddington (L_disk/L_Edd ~ 2) rapidly rotating black hole. The latter interpretation is preferred, due to the absence of such highly super-Eddington states in Galactic black holes and active galactic nuclei, and suggests that the ULX in M82 contains a black hole of 200-800 solar masses with nearly maximal spin. On long timescales, the source normally stays at a relatively low flux level with a regular 62-day orbital modulation and occasionally exhibits irregular flaring activity. The thermal dominant states are all found during outbursts.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑